Furnace for producing chemical changes



A. IVIcD. DUCKHAIVI.

FURNACE FOR PRODUCING CHEMICAL CHANGES.

APPLICATION FILED DECl 28, I92I.

Patented Nov. 21, 1922.

A. IVIcD. DUCKHAIVI.

FURNACE FOR PRODUCING CHEMICAL CHANGES.

APPLICATION FILED DEC. 28. V921.

Patented Nov. 21, 1922.

4 SHEETS-SHEET 2.

mmm

A. IVIc'D. DUCKHANI.

FURNACE FOR PRODUCING CHEMICAL CHANGES.

APPLICATION FILED DEC. 278, 192I.

lDatented Nov. 21, N22i` 4 SHEETS-SHEET 3.

A. IVIcD. DUCKHAIVI.

FURNACE FOR PRODUCING CHEMICAL CHANGES.

APPLICATION FILED DEC. 28, 192|.

Patented Nov. 21, 1922.

4 SHEETS-SHEET 4.

yale all continuously-1n; a closed-furnace; f

Y mufllefurnace containing -a-travelling plat- GALL Dnonnanrgyafsubl Great lritainiit residing Chemical ,Change V is a specification.

land, ha've invented'certam" newgand ,'useful Imprvements` jilr@ Furn'aces'ff l L' Producing v ,VW

ab e that the processshouldjbe vcatrr1'-e'cl outv For this purpose 'lf-construct an annular form or the like, in such a mannerthat the muflie is completelyA closed and the 'materiali is charged into and-.discharged from the i muiiie without interrupting the operation of thefurnace.

rlhe material to beheated is conveyed in the muiile on trucksor an annular platform rlthe charging ofthe material maybe by -means of a gas-tight feedingdevice and Achute, and a vertcall plate in front of the c arging chute, in theV of 'a- 'kind known in. annular furnaces'or kilns, but preferably constructed so that the material may loe-distributed on the carrying surface so asv to be in close proximity toA r the heated roof of the muiiewhich roof radiates heat on to the material.

adjustable striking direction of travelof the material, may determine the thickness of layer and the mode f l of distribution of the material onthe carrycharging device should be as far removed -ing surface.y lt is 'advantageous thatthe as Vmayf be lfrom 4the hottest zone a ofy combustion in the furnace. The discharging or removin device is preferably immediately behin the charging device and may lconsist of a bucket conveyer or the' like,

' which removes the material that has 'been after a certain number of piled up by an adjustable scraper which ma be set to remove the whole of the material or only the upper portion of the layer. When trucksa-re used the scraping device may be set at an an le to the path of the trucks, the material eing thus transferred from the truck surface to the side of the muile and discharged vthrough a chute which is closed by a gas-tight discharging device. The charging and'discharging may be'continuous or may be timed to occur only revolutions of the carrying surface.

hic the`followingtiffanyt desired gas' fr-other agentor vfor M escape"of,elastic-fluid;v Y -In 'the heati g offsubstancesi for lpromotin v'chemical 'change itis frequently .desirmilie for admission f :In'the-accompanyin drawin l and" 2l 'aredeveloped Fongitu gs, gs*

.arranged thmugh' dinal 4 vertical sections i through a furnace 'constructed accerding to this invention and shownin sectlonal plandrawn 'to Ia lreduced scale,- in Fig. 9. Fig. 3 isa crosss'ection of line 34-3 lof F 1g. 1 and Figs. 4, 5,16, 7 and S'are cross sections respectively on lines 4 4,

.2. Referring to Fig. v9, the urnace is constructed of concentric walls a at the centre` of which is a chimney b connected with the furnace through a fine e shewn in dotted lines.l The walls are carried on girders Z supported on plers y (Figs. l, 2 and 3) and the space between the inner of these girdersisclosed b plates'd1 (Figs. 5 and 8). 'At .equiangu ar distances apart the ates carry depending pockets d2 (Figs. 3 and 4:) which contain bearingsfor rollers e. 0n the latter are supported the .flan es of van annular ginder f carrying an annu ar platform g constructed of hollow brickwork filled with concrete g4, and the upper surface of the platformisv formed as a shallow trough having its'bottom Z of convex .cross section of radius similar to that of the roof h spanning the spacel between the walls a; and forming with these and plates all, the muiiie chamber.

The girder f carries a'rack f1 which is in gear with'a suitably driven pinion f2 (Fig.

the

7) so that the .platform is continuously ro- The material (inthis casea pulverulent solid) ris fed continuously into the trough ofthe platform through al as-tight feeding device v y".and a chute 'gl (Fig. 4) ata part of the muHe which is not-heated by the iiues presently to be described. The direction of travel being that shown by the' arrow in Figs. 1 and 2, the forwardside of the chute g1 carries an ad'ustable plate g2' (Fig. 2) which'serves to etermine the depth of the layer of material in the vtrough.

The roof h ofthe muiiie is heated by combustion of'gases in the heating flue z, the

draught being in the direction oplposite that ofthe platform, namely from t el air inlet i to the waste glas outlet h (Fig. l) and chimney Hue c, t e former bemg i front of the charging .chute g.

The gas enters the iue z through lports m,

' more or less diametrically .op osite the chargin chute g1 and considera ly in advance o the air inlets i (Fig. 9) thus the portion of the flue between these points serves for preheating the air and at the same time coolin the material.

Immediately be ind the vcharging chute g1 is the device for removing't e material; This consists ofa casing n containing a bucket-conveyor 0 suitably driven from the 4shaft of vpinion f2, for instance, as indicated .in Fig. 7. The front side of the casi-ng car- .v

ries a scraper plate p1 which arrests the material contained in the trough and enables it'to be picked up by the buckets of the oo nveyor and discharged into a horizontal a 1r tight worm conveyor p (Fig. 7) from which it is discharged vice q.

The furnace thus described in detail is airtight because it is intended for heating a material in an atmosphere of gas other than air. For supplying the `gas to the muflle ,chamberl thereis provided a liuc 1' above the heating flue z to which the gas is supplied through port e. From'here it travels in direction opposite to that of the lheating gas to short vertical liues t which connect the flue r Iwith the interior of the 'muiile (Fig. 3). Passing through these into the muliie, the gas reverses its direction and travels to the outlet u where it leaves the mulile by `passages lu.

'w is a heat insulating'air-space.

At the part -of the furnace where the material is char edf and discharged there are preferably sustituted for the roof .of the mulile, removable plates which permit of inspection and repair of the surface of the platform.

Having thus described the nature of my said inventionand the best means I know of carrying the same into practical effect, I claim:- l

1. A mullie furnace for producing chemie charging material on to the said platform without interrupting the operation of the rectly in .f

by an air-tight rotary defurnace and ,means for dischargin the ma- .terial from the platform wlthout'interguptf 'ingthe operation of the furnace, 1

3. A muffle furnace for producingelmini l calchanges comprising acompletely closed vannular chamber, means Yfor directly heating the roof only of the said chamber,''al travel- V` ling platform within the said chamber means for charging material on tothe sai platform without interrupting the operation of the furnaceand means for discharging the material from the platform without interrupting the operation o'f the furnace.

4, `A mufile furnace ,for producing 'chemical changes comprising a-com letely closed ,annular'chamben a travellin yp atform within the. said chamber having vits upper surface inclose proximity to the roof of the chamber,- means for directly heating the roof only of the said chamber, means for charging ma- -terial on to the said platform without mterrupting the operation of the furnace Aand= means for discharging theA material from the platform Withoutl interrupting the operation ofthe furnace. t

5. A muiiie furnace for producin chemical changes comprising a complete y closed annular chamber a travelling platform within the said chamber having its upper surface in close proximity to the roof vof the chamber and of such cross section that the said surface isequidistant from the roof throughout the cross section, meansl for directly heating the roof only fof the said chamber, means for charging material on to the said platform 4without interrupting the operation of the furnace and means for discharging the material from the platform without interrupting the operation of the furnace.

6. A muiile furnace for producing chemical changes comprising a .completely closed annular chamber, a travelling platform within the said chamber adapted 'to carry thematerial in such a manner that the material does not touch the heated surface of the. chamber, means for charging material on to the'said platform without interrupting the operation of the furnace and means for discharging the material from the platformwithout interrupting the operation of the furnace.

7. A muille furnace for producing chemical changes comprising a completely closed annular chamber, af travelling platform within the said chamber,.a heating flue above the roof of the chamber, a liuc above the.

said heating flue, portsv for admission of as into the latter liue, and communication e tween the latter liuc and the interior of the chamber such that gas preheated by the heating flue canbe passed into the chamber.

, 8. A muilie furnace for producing chemi cal changes comprising a completely closed annular chamber, .a travelling platform iso Within the said chamber, a flue above. the roof of the chamber, a Waste gas ue, a conf nection of the latter flue with the iue above the roof of the chamber, a ldevice for feeding the material von to the said platform i.

which device is placed near and behind the said connection in the direction of travel of the material in the chamber, gas inlets 'to the said flue above the chamber diametrically opposite to the said device and air inlets to the Hue above the chamber near and behind the said device.

9. A mulle furnace for producing chemimaterial on t0 the saidplatforin without interrupting the operation of the furnace, means for discharging the material from the platform Without interrupting the operation ofthe fura'ce and means for setting the discharging means so as to remove any desired thickness of the material.

Intestimony whereof I have signed my name to this specification.v

, ARTHUR McDOUGALL DUCKHAM. 

